中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Fracture stiffness evaluation with waterless cryogenic treatment and its implication in fluid flowability of treated coals

文献类型:期刊论文

作者Yang, Yun1,2; Liu, Shimin1,2; Chang, Xin3
刊名INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
出版日期2021-06-01
卷号142期号:-页码:18
ISSN号1365-1609
关键词Cryogenic treatment Fracture stiffness Sonic velocity Coal
DOI10.1016/j.ijrmms.2021.104727
英文摘要Cryogenic fracturing using liquid nitrogen is a waterless and environmentally friendly formation stimulation method for creating complex fracture networks effectively. This study developed a non-destructive geophysical technique using seismic measurements to probe fluid flow through coal and ascertain the effectiveness of cryogenic fracturing. A theoretical model is established to determine the fracture stiffness of coal inverted from wave velocities, which serves as the nexus for correlating the hydraulic and seismic properties of fractures. In response to thermal shock and frost forces, visible cracks are observed on coal surfaces that deteriorate the mechanical properties of the coal bulk. Consequently, the wave velocity of frozen coal specimens exhibits a general decreasing trend with freezing time under both dry and saturated conditions. For a gas-filled specimen, both the normal and shear fracture stiffness decrease monotonically with freezing time as more cracks are created in the coal bulk. For a water-filled specimen, ice formation due to cryogenic treatment leads to grouting of the coal bulk. Accordingly, the fracture stiffness of wet coal increases initially and then decreases with freezing time. A coalbed with higher water saturation is preferable when applying cryogenic fracturing because fluidfilled cracks can endure larger cryogenic forces before complete failure, and the contained water aggravates coal breaking as ice pressure builds up from the volumetric expansion of the water-ice phase transition and applies additional splitting forces on pre-existing or induced fractures and cleats. Also confirmed is that the stiffness ratio is sensitive to fluid content. The measured stiffness ratio is 0.7-0.9 for dry coal but less than 0.3 for saturated coal. The present findings provide a basis for realistic estimation of coal stiffness ratio for future discrete fracture network modeling.
WOS研究方向Engineering ; Mining & Mineral Processing
语种英语
出版者PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号WOS:000663073700002
源URL[http://119.78.100.198/handle/2S6PX9GI/27538]  
专题中科院武汉岩土力学所
作者单位1.Penn State Univ, G3 Ctr, Dept Energy & Mineral Engn, University Pk, PA 16802 USA
2.Penn State Univ, EMS Energy Inst, University Pk, PA 16802 USA
3.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Peoples R China
推荐引用方式
GB/T 7714
Yang, Yun,Liu, Shimin,Chang, Xin. Fracture stiffness evaluation with waterless cryogenic treatment and its implication in fluid flowability of treated coals[J]. INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES,2021,142(-):18.
APA Yang, Yun,Liu, Shimin,&Chang, Xin.(2021).Fracture stiffness evaluation with waterless cryogenic treatment and its implication in fluid flowability of treated coals.INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES,142(-),18.
MLA Yang, Yun,et al."Fracture stiffness evaluation with waterless cryogenic treatment and its implication in fluid flowability of treated coals".INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES 142.-(2021):18.

入库方式: OAI收割

来源:武汉岩土力学研究所

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